Means for controlling the supply of liquid fuel to internal-combustion prime movers



April 17, 1951 E. A. WATSON A MEANS FOR CONTROLLING THE SUPPLY OF LIQUIDFUEL 'ro INTERNAL-COMBUSTION PRIME MOVERS 2 Sheets-Sheet 1 Filed Feb. 6,1946 Apnl 17, 1951 E. A. WATSON 59,

mums FOR CONTROLLING THE SUPPLY OF LIQUID FUEL T0 INTERNAL-COMBUSTIONPRIME uovsas Filed Feb. 6, 1946 2 Sheets-Sheet Patented Apr. 17, 1951MEANS FOR CONTROLLING THE SUPPLY OF LIQUID FUEL TO IN TERNAL-COMBUSTIONPRIME I MOVERS r Ernest Ansley Watson, Birmingham, England,- assignor toJoseph Lucas Limited, Birmingham, England Application February 6, 1946,Serial No. 645,742 In Great Britain January 1, 1946 Section 1, PublicLaw 690, August 8, 1946 Patent expires January 1, 1966 6 Claims. (01.103-11) This invention relates to systems in which liquid fuel issupplied to an internal combustion prime mover by a variable-deliverypump, the means which control the output of the pump end of the lever inthe direction for closing the w which is adapted to act on the lever qin oppo sition to the spring 22, the plunger being respon sive to fluidpressure in a sub-chamber a: on the being responsive at least in part tofluid pressure chamber 1. Moreover, the compartment is condependent onthe speed of the prime mover. nected by pipes y, z to the tank 0 at thesupply The object of the invention is to enable any side of the pump a.The other compartment u desired part of the available fluid pressure tobe is provided with an opening 2 leading to the used for actuating theoutput controlling means 10 atmosphere, and contains an evacuatedcapsule of th pump -3 adapted to act on the lever q in opposition to rIn the accompanying sheets of explanatory the spring 0. drawings: VAdjustment of the swash plate b of the pump a' Figure 1 is adiagrammatic part sectional side to vary the'pump output is efiectedautomatically view illustrating one form of the invention ap-' by thepiston 71. in response to movement of the plied to a variable deliverypump, and Figure-2 lever q. r 1 is a section on the line 22 of Figure 1.In carrying the invention into effect as shown Figure 3 is a sectionalside view illustrating a n gures 1 and 2, I provide a by-pass devicemodified feature, having a hollow body part 4 adapted to form a Figures4 and 5 are similar sectional views shallow cylindrical chamber in whichis mounted illustrating respectively two modified forms of a rotatabledi 5 h ng a p ai Outer perip y, t invention, 7 the latter and the innerperiphery of the cham- Figure 6 is a similar view to Figure 1 illustratbfor ing a narrow annular space 6 through ing another modified form ofthe invention. which liquid fuel can flow. At diametrically D-. e InFigure 1 it indicates a variable-delivery posite positions the body part4 is formed with a pump of t swash plate t whi i adapted pair of ports7, 8 which communicate with the to be driven in any convenient manner bythe annular pace 6. The port 1 serves as a connecinternal combustionprime mover (not shown) to tion for One end of a p 9 Which at ts Ot erbe supplied with liquid fuel by the pump, the outn i connected t the pmp d liv ry pip iput of the pump being controlled in known man- Theother port 8 serves as a connection for one her by an angularlyadjustable swash plate b. end of the P pe 2! Which t its other end iscon- Liquid fuel is supplied from a tank 0 to the pump nected to thecompartment t of the cha er a by a pipe d, and is delivered by the pumpto the and which at an intermediate position is conjets e of the primemover through another pipe f. nected by the pip 2 t0 the tank 0 at theSupply The swash plate b is connected by a rod-g to a d O t e pump a.When the pu ll is in piston h which is slidable in a cylindrical chem:action the annular space 6 in the body part 4 her 2' formed in thestationary part of the pump a, forms a by-pass by which some of theliquid in the piston being loaded by a spring 7. The end thedeliverypipefcan constantly be returned to of the chamber 2 towardswhich the piston h is the supply side of the pump a, and the dimen-jmovable by the spring :1 is connected by a pipe is sions of theannular'sp-ace are made such as wil to the delivery pipe I of the pumpa, and this end 40 set up a convenient pressure gradient between of thechamber also communicates with the other the two ports 1, 8. end of thechamber through arestricted passage The rotatable disc 5 is formed witha radial m. The latter end of the chamberi is connected passage Illleading from, t periphery of t by a pipe n to a vent 0 which at itsouter end disc to an axial passage H in the disc. The axial, forms aseating for a closure member p on one passage ll communicates with athird port l2-in end of a lever q in a chamber 1'. 5 one end of thehollow body part 4, this port serv- The leverqis secured ata positionintermediate ing as a connection for one end of a pipe I3 its ends to adiaphragm swhich serves as a fulwhich. at its other end is connected tothe sub-' crum for the lever, and divides the chamber r chamber a: onthe chamber 1'. Consequently presinto two o partments t, u. The vent ois sure fluid can flow vfromrthe annular space 6 in adapted tocommunicate with the compartment t the body part 4 .to the sub-chamber:r'where it under the control of the closure member 10 on the acts onthe adjacent end of the plunger 10 which lever q, and this compartmentcontains a comforms a part of the mechanism for controlling pressionspring 0 adapted'to act on the adjacent the pump output. Also the disc 5is rotatable manually or under ,inanual control (through the 1 medium ofan axial stem is on the disc and a lever l on the stem) to move theouter end of the radial passage H) to any desired position between theports 1, 8 and so vary the fluid pressure acting on the plunger 10. I

As an alternative to the disc 5 shown in Figures 1 and 2 I may employ aperipherally toothed disc as indicated by 5 in Figure 3.

Instead of having the form above described the by-pass device may haveany of a variety of forms two of which are illustrated in Figures 4 and5.

In the example shown in Figure 4 I employ a chambered body part 4 havinga pair of cylindrical ports 1 8 at its opposite ends, the outer ends ofthe ports serving respectively as connections for the pipes 9, ypreviously described. In each of the ports 1 8 is arranged a slidableflow-controlling plug 5 which may be of tapered form or of cylindricalform with one or more tapered grooves as 6 along its length. The twoplugs 5 are interconnected by and may be integral with a part [5 adaptedto receive linear movement from a crank or like mechanism ineluding apin H engaging a slot i8 in the said i part, the said mechanism beingoperable manually or under manual control. By operating the crank orlike mechanism the plugs 5 are moved so as simultaneously to increasethe effective area of one of the ports i 8 and decrease the other.Alternatively two separate plugs may be used, these being actuated by arotatable cam situated between their adjacent ends. In one side the bodypart 4 is provided with a third port ('2 which serves as a connectionfor the previously described pipe I3 whereby pressure fluid is conductedto the output controlling mechanism of the pump. By varying theeffective areas of the two first mentioned ports 7 8 thepressure of the.liquid in the body part 4 (and consequently the pressure acting on thepump controlling mechanism) is also varied.

In the example illustrated by Figure5 I employ a body part 4 providedwith three ports 1 8 and H2 which serve respectively as connections forthe pipes 9, y and [3 previously described. The ports '1 12 communicaterespectively with passages 59, 26 in the body part 4 and these passagesare interconnected by a third passage 2i in the body part. Also thethird passage 2! is connected at one end to the port 8 by a fourthpassage 22 in the body part 1 Moreover, fluid flow from the passage H)to the passage 2| is restricted by an adjustable member 23, and fluidfiow from the passage 22 to the port 8 is likewise restricted by anadjustable member 25. Further, fluid flow from. the passage 21 to thepassageZZis controllable by a flow-restricting member 25, the latterbeing adjustable by rack-and-pinion mechanism 25 from a lever 2'! whichis operable manually or under manual control. By adjusting theflow-restricting member 25, the fluid pressure in the passage 2! (andconsequently the pressure acting through the port H on the pumpcontrolling mechanism) is varied. 7

Instead of employing the pressure of fluid delivered by the pump foractuating the plunger 10 of the pump controlling mechanism shown inFigure 1, I may employ the delivery pressure of a blower driven by theprime mover. An example of this modification is illustrated in Figure 6in which parts similar or analogous to those shown in Figure 1 areindicated by the same reference characters sufiixed by 4. In the exampleillustrated in Figure 6 the sub,-

chamber r is divided by a diaphragm 28 into two compartmentsone of whichis provided with an air vent 2E and the other of which is connected bythe port l2 and a passage 30 to a pair of ports 7 8 The diaphragm 28serves to actuate the plunger'w The port 7 serves as a connec tion forone end of a pipe 33 which at its other end is connected to the outletof the compressor lable by a second flow-restricting member 37, the

latter being adjustable manually or under manual control. When thecompressor 34 is in action a portion of the air delivered by it isconstantly discharged to the atmosphere through the port 1 passage 36,and port 8, and the first mentioned flow-restricting member 36 sets up aconvenient pressure drop between the compressor outlet and the passage39 leading to the diaphragm 28. By adjusting the second flow'restrictingmember 31, the fluid pressure acting on the diaphragm 28 (andconsequently on the plunger w can be varied.

By this invention the control of the liquid fuel supply to an internalcombustion prime mover can be efiected in a very satisfactory manner.The invention is not, however, restricted, to the examples described, asits essential features may be embodied in a variety of forms.

Having'thus described my invention what I claim as new and desire tosecure by Letters Patent is: 1

1. A liquid fuel supply system comprising a variable delivery pump and amember responsive to fluid pressure for controlling the output of thepump, a by-pass device having in combination a pressure fluid inlet, apressure fluid outlet, a restricted passageway interconnecting the inletand outlet, 2. port which communicates with the passageway at a positionbetween the inlet and outlet, and means through which the pump controlmember is exposed to the fluid pressure at the said position within thepassageway, and adjustable means for establishing a variable pressuredrop in the passageway to vary the fiuid pressure acting on the saidmember.

2. A liquid fuel supply'system as claimed in claim I, in which theby-pass device comprises in combination a shallow cylindrical chamberprovided at diametrically opposite positions with the inlet and outlet,and at one side with the port, a rotatable disc mounted within thechainberso as to leave a narrow annular space between the outerpsriphery of the disc and the inner periphery of the chamber, the discbeing formed with a passageway through which the said space communicateswith the port, and manually controllable means for imparting rotationaladjusting movement to the disc.

3. A liquid fuel supply system as claimed in claim 1, in which theby-pass device comprises in combination a shallow cylindrical chamberprovide-cl at diametrically opposite positions with the inlet andoutlet, and at one side the port, a rotatable and peripherally tootheddisc mounted within the chamber so as to leave a narrow annular spacebetween the periphery of the disc and the inner periphery of the charm,her, the disc being. formed with a passagewaythrough which thesaid'space communicates with,-

4. A liquid fuel supply system as claimed in claim 1, in which theby-pass device comprises in combination a hollow body part provided atopposite ends with the inlet and outlet, and at one side with the port,a pair of slidable flowcontrolling plugs mounted respectively in theinlet and outlet, and manually controllable means for impartingsimultaneous adjusting movements to the plugs.

5. A liquid fuel supply system as claimed in claim 1, in which theby-pass device, comprises in combination a body part provided withpassages interconnecting the inlet and outlet and the port, a member forrestricting fluid flow from the inlet to the port and the outlet,another member for restricting fluid flow through the outlet; a thirdmember for restricting fluid flow between the port and the outlet, andmanually controllable means for varying the position of the thirdmember.

6. A liquid fuel supply system as claimed in claim 1, in which theby-pass device is provided at its inlet with a member for restrictingfluid flow between the inlet and outlet and the port, and at its outletwith an adjustable member for restricting fluid flow through the outlet.

ERNEST ANSLEY WATSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES BATENTS

